Labyrinth packing



May 23, 1939.

A. J. LARRECQ LABYRINTH PACKING Filed April 15,y 1958 Inventor:`*Anthony J. Lar Pecq,

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ls Att. CDT-Dey.

feci Patented May 23, 1939 inlTrzNT OFFICE LABYRINTH PACKING AnthonyJames Larrecq, Beachbluff, Mass., assignor to General Electric Company,a corporation of. New York Application April 15, 1938, Serial No.202,277

11 Claims.

\ pfradially extending packing elements or disks provided on the shaftof the rotating element `.which disks are provided on opposite sideswith a plurality of axially extending annular rings. The stationarypacking elements are also disk- "likein shap-e and are provided onopposite sides withaxially extending annular rings. These stationarypacking elements are so mounted on the `casing structure and' extendradially between the j'rotating elements that the rings `of the adjacent`Lfacesintermesh forming a tortuous passage to `baifie the fiow of thefluid, the leakage of which lit is `desired to prevent. d

`"Ihis type of packing is particularly desirable lbecause of therelativelyy short axial length for a .given number of throttling points.But in pro- "viding packings of this typeior elastic fluid tur- "Qbinesoperating with high temperature and high pressure elastic uid of theorder'of 1200 pounds ormore,` diiculties are encountered in effecting"asuitable seal. Heretofore in` packings of this type the radialelements to be carried by the f. shaft 'have each been formed withindividual sleeves which sleeves were then slipped over the end of theshaft and shrunk into position as alternate stationary and rotatableelements were I I. assembled. In the operation of the turbine,

owing to unequal ratios of expansion of the different parts, the sleevesof the rotating elements and permit leakage of elastic fluid along the`shaft. It will be readily understood that the `.loosening occursparticularlyr during the starting of `the turbine as the rotatingpacking `elements `which are `in direct contact .with the hightemperature fluid heat up morerapidlyjthan the ,"shaft Although theclearance between theshaft fand the inner packing member which is due to"55j" `It1is a further object of `this invention to pro- 3v previouslyshrunk onto the shaftbecome loose x35.

vide a new and improved arrangement Aof stationary packing elements foruse in a labyrinth packing of the type described, which stationaryelements may be readily assembled, and securely fastened in position. 5

-For a consideration of what I believe to be novel and myinvention,attention is directed to the following description and the claimsappended thereto in Connection with the accompanying drawing.

Referring to the drawing, Fig. l is a longitudinal view, partly insection, of a shaft packing embodying my invention and Fig. 2 is a planview showing in detail one of the stationary packing elements.

For the purpose of illustration, I `show my novel `labyrinth packingapplied for sealing the space between the shaft opening of a turbine andthe shaft extending therethrough. Obviously, it may be applied to anyrelatively rotatable members-@Q0 Referring to Fig. l of the drawing, IUindi- Cates a turbine casing and I I the turbine shaft extending throughan opening I2 therein. A plurality of axially spaced apart and radiallyextending disks or packing elements I3 are formed g5 integrally with theshaft each provided on opposite sides with a plurality of axiallyextending annular rings I 4. The stationary .packing units include diskelements I5 and I6, substantially identical in construction, arrangedbetween ad-"to jacent rotating elements back to back with spacer disksI1 therebetween. The stationary packing elements are provided on theirfaces with a plurality of axially extending annular rings I8 spacedapart upon the surface so as to intermeshr between the annular rings I4of the rotating elements when in assembled position. The stationaryelements are provided at their peripheries with flange rings I9extending axially from the face surfaces. The flange rings of thestationaryao disks assembled on opposite sides of `a shaft packingelement are adapted to abut against each other around the edge of theshaft element thereby insuring the proper clearance between the"relatively movable elements, which clearanceli may be determined by thewidth of the flange rings.

` The stationary packing elements I5 or I6 are divided into a pluralityof sectorsy I5 as shown in Fig. 2 to permit the assembly of the elementsI"50 within the space between the rotatable elements and around theshaft. After a pair of stationary disks such as I5 and I6 have beenassembled back to back in position about theA shaft and beu tween twoadjacent rotatable disks, the spacer llo' disk I1 is insertedtherebetween to wedge them axially apart so as to cause an intermeshingof the annular rings i8 thereof with the annular rings I4 of therotatable elements i3. The spacer disks are also suitably sectoredsimilar to the stationary packing elements to facilitate the assemblythereof about the shaft.

The spacer disks maybe provided at the outer edges with rims 20 whichextend axially upon both sides thereof. As shown, the inner edges ofthese rims are adapted to seat within annular grooves 2i formed in theperipheries of the stationary packing disks. The entire assembly ofstationary parts may be secured in position by means of the housingparts 22 and 23 fitted thereover. The shoulder 2li provided on the innerend wall of the housing its into the peripheral groove ofthe outermoststationary packing element to retain the sectors of this element inposition. As the housing is fastened, as by bolts 25, to the end wall ofthe turbine casing lil, the .stationary packing parts are rigidlyclamped between the end wall of the housing and the turbine casing. Theouter surfaces of the rims 2Q extending from the spacer disks areengaged by the inner walls of the housing so as to preclude radialshifting of the sectors making up the spacer disks. Accordingly, thesectors of the stationary packing disks are also thereby securelyretained in the proper position.

It is desirable to provide annular spaces or chambers such as 2l'between the stationary packing elements and the inner wall of thehousing into which chambers the heated elastic fluid may pass for thepurpose of expanding the entire assembly of parts uniformly uponstarting of the turbine and for effecting a more ecient seal. Apertures28 may be provided in the rims of one or more of the sectors of thestationary packing disks for conducting elastic fluid from the shaftpassage into such annular chambers.

, By the arrangement shown it is readily seen that the packing may beeasily disassembled for inspection or repair without removing the rotorfrom the casing or even without removing the upper half of the turbinecasing. By removing the housing parts 22 and 23, the spacer disks may bewithdrawn which will then allow the stationary packing disks to be movedaxially and the rings thereof to be withdrawn from the intermeshingposition. The packing disks may be then removed by sectors radiallyoutward from between the shaft elements.

While I have described the rotatable packing elements as being formedintegrally with the shaft, it is obvious that these elements may beformed integrally upon a separate sleeve. The sleeve may be fitted ontothe shaft in any suitable manner so as to permit replacement in theevent of 'serious damage thereto. The sleeve, for example, may beremovably secured to the shaft in a manner similar to that shown inPatent 1,895,930, J unggren, assigned to the General Electric Company,so as to preclude leakage of fluid between the sleeve and the shaft.

While I have shown my invention in but one modification, it will beobvious to those skilled in the art that it is susceptible of variouschanges Without departing from the spirit thereof and I desire,therefore, to have it understood that the arrangement shown is onlyillustrative and that I intend Vby the appended claims to Vinclude allsuch modifications as fall within .the true spirit of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth packing for said opening comprising a pluralityof axially spaced apart disk packing elements integrally connectedtogether and mounted on said shaft, stationary packing units eachcomprising a pair of disks for assembly between adjacent shaft elements,means for spacing said disks of each stationary packing unit axiallyapart, peripheral rims provided on said stationary packing disks forengaging over the edge of said shaft elements and spacing saidstationary packing disks from said shaft elements, a housing for said`packing assembly, a plurality of annular chambers provided between saidhousing and said stationary packing units and passages through said rimscommunicating with said annular chambers.

2. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth packing for said opening comprising a pluralityof axially spaced apart disk packing elements provided on said shaft,said elements being provided on the sides with a plurality of axiallyextending concentric rings, stationary packing units for assemblybetween adjacent shaft elements, each stationary packing unit comprisinga pair of sectored disks, said disks being provided on the face surfaceswith a'plurality of axially extending concentric rings, a peripheral rimextending from the face surface of each of saidv pair of disks, meansfor spacing said disks of each stationary packing unit axially apart ininter-meshing relan35 tionship with said shaft elements, the peripheralrims of stationary packing disks on opposite sides of each shaft elementengaging over the edge of said shaft elements for spacing saidstationary packing disks from said shaft elements, a housing forclamping said packing assembly to said casing and means between saidhousing and said stationary packing disks for precluding radial shiftingof the sectors of said disks.

3. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth packing for said opening comprising a pluralityof axially spaced apart disk packing elements formed integrally togetheron said shaft, said elements being provided on facing sides with aplurality of axially extending rings, a stationary packing unitcomprising a pair of sectored disks for assembly between a pair of saidshaft elements, said disks being provided on the face surfaces with aplurality of axially extending rings, a sectored spacer disk for spacingthe sta" tionary packing disks of said pair axially apart so that therings on the faces thereof intermesh with the rings of said shaftelements, means including said spacer disk for precluding radialIshifting of said stationary packing elements, a housing for said packingassembly for precluding shifting of said spacer disk sectors.

4. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth65 axially extending rings, a stationary packingunit.

comprising a pair of sectored disks for assembly between adjacent shaftelementsjsaid sectored l disks being provided on one side with aplurality of axially extending rings, a sectored spacer disk for spacingsaid stationary packing elements in `1g;

intermeshing relationship with said shaft elements, said spacer diskhaving a peripheral rim extending axially on both sides thereof, theinner surface of said rim engaging said stationary packing disks, ahousing tted over said packing assembly and engaging the outer surfaceof said spacer disk rim.

` 5. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth `rim extending axially from the face surface of,each of said pair of disks, a sectored spacer disk for spacing saiddisks of each stationary packing unit axially apart in intermeshingrelationship with said shaft elements, the periph- Y eral rims ofstationary packing disks on opposite sides of each shaft elementengaging over the l edge of said shaft elements for spacing saidstathrough an opening in said casing, a labyrinth packing for saidopening comprising a plurality of axially spaced apart disk packingelements lintegrally connected together and mounted on said shaft, thefaces of said elements being provided with a plurality of axiallyextending concentric rings, a stationary packing unit coma prising apair of sectored disks for assembly between a pair of said shaftelements, said sectored packing unit and said spacer disk to saidcasing.

'7. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth packing for said opening comprising a plurality`of axially spaced apart disk packing elements provided on said shaft,said elements being provided on opposite sides with a plurality ofaxially extending concentric rings, stationary packing units forassembly between adjacent shaft elements, each stationary packing unitcomprising x a pair of sectored disks, said disks being provided on theface surfaces with a plurality of axially extending concentric rings,means for spacing said disks of each stationary packing unit axiallyapart. in intermeshing relationship with said shaft elements, means onsaid stationary packing disks for spacing said stationary packing disksfrom said shaft elements and means for securing said stationary packingunits.

8. In combination, a casing, a shaft extending through an opening insaid casing, a labyrinth packing for said opening comprising a pluralityof axially spaced apart disk packing elements integrally connectedtogether on said shaft, said elements being provided on opposite sideswith a plurality of axially extending concentric rings, stationarypacking units for assembly between adjacent shaft elements, saidstationary packing units each comprising a pair of sectored disks, eachof said disks being provided on the face surfaces with a plurality ofaxially extending concentric rings, sectoredspacer disks for spacing thedisks of each of said pair axially apart into intermeshing relationshipwith said shaft elements, means for securing said stationary packingelements and said spacer disks to said casing in spaced relationshipwith respect to said shaft elements.

9. A labyrinth packing for shaft openings comprising a plurality ofaxially spaced apart rotatable disk packing elements, a stationarypacking unit for assembly between adjacent rotatable elements, saidpacking unit comprising a pair of sectored disks and means for spacingsaid sectored disks axially apart and means provided on said sectoreddisks for retaining said stationary packing unit in spaced relationshipwith respect to said rotatable packing elements during the normaloperative position of the latter.

l0. A labyrinth packing for shaft openings comprising a plurality ofspaced apart rotatable packing elements rigidly secured together,stationary packing units for assembly between adjacent rotatableelements and into cooperative relationship therewith, each of saidpacking units comprising a pair of sectored disks, means for spacing thedisks of each pair axially apart, and means provided on said sectoreddisks for spacing said sectored disks with respect to said rotatablepacking elements during the normal operative position of the latter.

11. A labyrinth packing for shaft openings comprising a plurality ofspaced apart rotatable packing elements integrally connected together,stationary packing units between adjacent rotatable elements, each ofsaid packing units comprising a pair of sectored disks, means forspacing the disks of each pair axially apart into cooperativerelationship with said rotatable elements, means provided on saidsectored disks for spacing said packing units with respect to saidrotatable elements during the normal operative position of the latterand a housing fitted over said packing for securing said stationarypacking units in position.

ANTHONY JAMES LARRECQ.

